The four stroke internal combustion engine has changed little since its inception over 100 years ago. The 1973 energy crisis spurred public and governmental requirements for more fuel-efficient automobiles during the 1970's. Increases in fuel efficiency were brought about primarily by the introduction of small displacement engines and smaller, lighter weight automobiles. The Japanese, already manufacturing autos with these characteristics, quickly gained market share at the expense of U.S. automakers. However, all of these down-sized automobiles lacked an important consumer want, good acceleration. To satisfy this complaint, manufacturers used several methods to increase output while still meeting government mandated mileage levels. Primarily, these methods included using already developed performance enhancing technologies such as the use of larger valves, higher compression ratios, higher r.p.m.'s, more valves per cylinder, and super-charging or turbo-charging. While these efforts produced engines with outputs comparable to pre-1973 levels and good fuel economy, they are also very costly to produce.
Today, another crisis is emerging in the form of increasing requirements for reducing emissions from vehicles. The most efficient method to reduce emissions is not to produce them in the first place. In this regard, electric vehicles may eventually prove successful, but as of now, technical problems remain and these vehicles will likely be costly to produce. 0n the other hand, reducing emissions produced by current engines is most effectively done by burning less fuel which in turn is most effectively accomplished by reducing engine displacement. As conventional poppet engines are reaching the limits of development, this would seem to imply a return to the poor performance automobiles of the seventies. While some performance gains can be recaptured through reduced vehicle weight and other technical improvements, it is expected that the resultant vehicle will not match current performance levels and be more costly to produce. This trade-off creates a difficult dilemma for the auto manufacturer. The public demand for clean air on one hand must be balanced against individual consumer demands for high performance and low costs on the other.
What is needed to meet the dilemma resulting from society's demand for lower emission engines is a compact, lightweight engine capable of producing markedly increased output per liter without increasing costs. Then, a smaller displacement version of this "superengine" could match current performance levels and allow any cost savings from the engine to offset cost increases incurred by other fuel conserving measures. In this manner, both the public demand for lower emissions and the individual consumer demands for performance and can be met at no additional costs.